A number of different closures for selectively closing an opening in a container wall are known in the are. Two excellent examples of such closures are those shown in my U.S. Pat. Nos. 4,736,858 for A Selectively Closable Container Closure and No. 4,775,065 for A Tamper-Resistant Dispensing Closure.
In these U.S. patents, an insert is provided having a through opening to the container space. The closure further includes a base element which is secured to the container wall and acts to retain the insert on the container wall inwardly of a control element which is swingably mounted to the base element for selectively disposing a stopper portion in the opening of the insert.
It is also known to mount a closure on a container wherein the container wall defines the opening, thus eliminating the need for the separate insert. One such closure structure is shown in Takamitsu Nozawa et al U.S. Pat. No. 4,291,818.